Determinants of the cuff-leak test: a physiological study

Table 2 Model study: protocol A

Parameter	Normal pattern			Restrictive pattern			Obstructive pattern
	V' = 1	V' = 0.8	V' = 0.6	V' = 1	V' = 0.8	V' = 0.6	V' = 1	V' = 0.8	V' = 0.6
Large area
Leak_pause (ml)	191 ± 7	196 ± 6	190 ± 4	190 ± 13	190 ± 15	190 ± 6	196 ± 5	185 ± 6	187 ± 6
Leak_conv (ml)	298 ± 6	315 ± 3^a	339 ± 4^ab	303 ± 6	330 ± 2^a	358 ± 2^ab	308 ± 7	309 ± 5	320 ± 10^ab
Small area
Leak_pause (ml)	146 ± 2	135 ± 5	135 ± 4	147 ± 8	148 ± 12	137 ± 4	146 ± 9	139 ± 6	141 ± 11
Leak_conv (ml)	239 ± 7	228 ± 3	244 ± 4^ab	249 ± 10	243 ± 4	269 ± 7^ab	243 ± 14	234 ± 4	254 ± 6^ab

Results are means ± SD. V', constant inspiratory flow (litre/s); Leak_conv, cuff-leak volume measured when the cuff remained deflated during both inspiration and expiration; Leak_pause, cuff-leak volume measured when the cuff was deflated at the end of 3 s of inspiratory pause.
^aSignificantly different from the corresponding value at V'_I = 1 litre/s.
^bSignificantly different from the corresponding value at V'_I = 0.8 litre/s.

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